Refractory metal-titanium nitride conductive structures

Abstract

The present invention provides a conductive structure for use in semiconductor devices. The structure can be used to interconnect the various diffusion regions or electrodes of devices formed on a processed semiconductor substrate to a layer of metal, to interconnect overlying layers of metal or to provide the gate electrode of an FET device formed on the surface of a semiconductor substrate. Various embodiments of the invention are described, but in broad form the active metallurgy of the present invention comprises a thin continuous layer to titanium--titanium nitride and a thick layer of a refractory metal, e.g. tungsten, overlying the titanium nitride layer.

What is claimed is: 
     
       1. A conductive structure formed on a processed semiconductor substrate, comprising: a first layer of patterned metallurgy;   a layer of passivating glass on said first layer of patterned metallurgy, said layer of passivating glass having an upper surface and having an opening therein to expose a portion of said first layer of patterned metallurgy;   a continuous layer of Ti-TiN lining only said opening in electrical contact with said first layer of patterned metallurgy, said continuous layer of Ti-TiN having a lower surface consisting of Ti and an upper surface consisting of stoichiometric TiN, at least an upper half of said continuous layer of Ti-TiN consisting of TiN,   a layer of tungsten on said continuous layer of Ti-TiN, said tungsten substantially filling the remainder of said opening such that no tungsten is present on said upper surface of said layer of passivating glass; and   a second layer of patterned metallurgy in electrical contact with said layer of tungsten and, via said continuous layer of Ti-TiN, in electrical contact with said first layer of patterned metallurgy.   
     
     
       2. A conductive structure formed on a processed semiconductor substrate according to claim 1 wherein said passivating glass is borophosphosilicate glass. 
     
     
       3. A conductive structure formed on a processed semiconductor substrate according to claim 1 wherein said passivating glass is phosphosilicate glass.